package com.yunhuajinfu.view;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.CornerPathEffect;
import android.graphics.Paint;
import android.graphics.Path;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.util.Log;
import android.util.TypedValue;
import android.view.Gravity;
import android.view.View;
import android.view.WindowManager;
import android.widget.LinearLayout;
import android.widget.TextView;

import com.yunhuajinfu.R;

import java.util.List;

/**
 * Created by ekikousei易皇星 on 16/11/19.
 * E-mail:13764664731@163.com
 * Signature:缘分是本书,翻的不经意会错过,读的太认真会流泪!!
 * <p/>
 * TODO:类描述:
 */
public class ViewPagerIndicator extends LinearLayout {

    /**
     * 绘制三角形的画笔
     */
    private Paint mPaint;
    /**
     * path构成一个三角形
     */
    private Path mPath;
    /**
     * 三角形的宽度
     */
    private int mTriangleWidth;
    /**
     * 三角形的高度
     */
    private int mTriangleHeight;


    /**
     * 三角形的宽度为单个Tab的1/6
     */
    private static final float RADIO_TRIANGEL = 1.0f / 6;
    /**
     * 三角形的最大宽度
     */
    private final int DIMENSION_TRIANGEL_WIDTH = (int) (getScreenWidth() / 3 * RADIO_TRIANGEL);


    /**
     * 初始时，三角形指示器的偏移量
     */
    private int mInitTranslationX;
    /**
     * 手指滑动时的偏移量
     */
    private float mTranslationX;


    /**
     * 默认的Tab数量
     */
    private static final int COUNT_DEFAULT_TAB = 4;
    /**
     * tab数量
     */
    private int mTabVisibleCount = COUNT_DEFAULT_TAB;


    /**
     * tab上的内容
     */
    private List<String> mTabTitles;
    /**
     * 与之绑定的ViewPager
     */
    public ViewPager mViewPager;


    /**
     * 标题正常时的颜色
     */
    private static final int COLOR_TEXT_NORMAL = 0x77FFFFFF;
    /**
     * 标题选中时的颜色
     */
    private static final int COLOR_TEXT_HIGHLIGHTCOLOR = 0xFFFFFFFF;


    public ViewPagerIndicator(Context context)
    {
        this(context, null);
    }


    public ViewPagerIndicator(Context context, AttributeSet attrs)
    {
        super(context, attrs);


// 获得自定义属性，tab的数量
        TypedArray a = context.obtainStyledAttributes(attrs,
                R.styleable.ViewPagerIndicator);
        mTabVisibleCount = a.getInt(R.styleable.ViewPagerIndicator_item_count,
                COUNT_DEFAULT_TAB);
        if (mTabVisibleCount < 0)
            mTabVisibleCount = COUNT_DEFAULT_TAB;
        a.recycle();


// 初始化画笔
        mPaint = new Paint();
        mPaint.setAntiAlias(true);
        mPaint.setColor(Color.parseColor("#888888"));
        mPaint.setStyle(Paint.Style.FILL);
        mPaint.setPathEffect(new CornerPathEffect(3));


    }


    /**
     * 绘制指示器
     */
    @Override
    protected void dispatchDraw(Canvas canvas)
    {
        canvas.save();
// 画笔平移到正确的位置
        canvas.translate(mInitTranslationX + mTranslationX, getHeight() + 1);
        canvas.drawPath(mPath, mPaint);
        canvas.restore();


        super.dispatchDraw(canvas);
    }


    /**
     * 初始化三角形的宽度
     */
    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh)
    {
        super.onSizeChanged(w, h, oldw, oldh);
        mTriangleWidth = (int) (w / mTabVisibleCount * RADIO_TRIANGEL);// 1/6 of
// width
        mTriangleWidth = Math.min(DIMENSION_TRIANGEL_WIDTH, mTriangleWidth);


// 初始化三角形
        initTriangle();


// 初始时的偏移量
        mInitTranslationX = getWidth() / mTabVisibleCount / 2 - mTriangleWidth
                / 2;
    }


    /**
     * 设置可见的tab的数量
     *
     * @param count
     */
    public void setVisibleTabCount(int count)
    {
        this.mTabVisibleCount = count;
    }


    /**
     * 设置tab的标题内容 可选，可以自己在布局文件中写死
     *
     * @param datas
     */
    public void setTabItemTitles(List<String> datas)
    {
// 如果传入的list有值，则移除布局文件中设置的view
        if (datas != null && datas.size() > 0)
        {
            this.removeAllViews();
            this.mTabTitles = datas;


            for (String title : mTabTitles)
            {
// 添加view
                addView(generateTextView(title));
            }
// 设置item的click事件
            setItemClickEvent();
        }


    }


    /**
     * 对外的ViewPager的回调接口
     *
     * @author zhy
     *
     */
    public interface PageChangeListener
    {
        public void onPageScrolled(int position, float positionOffset,
                                   int positionOffsetPixels);


        public void onPageSelected(int position);


        public void onPageScrollStateChanged(int state);
    }


    // 对外的ViewPager的回调接口
    private PageChangeListener onPageChangeListener;


    // 对外的ViewPager的回调接口的设置
    public void setOnPageChangeListener(PageChangeListener pageChangeListener)
    {
        this.onPageChangeListener = pageChangeListener;
    }


    // 设置关联的ViewPager
    public void setViewPager(ViewPager mViewPager, int pos)
    {
        this.mViewPager = mViewPager;


        mViewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener()
        {
            @Override
            public void onPageSelected(int position)
            {
// 设置字体颜色高亮
                resetTextViewColor();
                highLightTextView(position);


// 回调
                if (onPageChangeListener != null)
                {
                    onPageChangeListener.onPageSelected(position);
                }
            }


            @Override
            public void onPageScrolled(int position, float positionOffset,
                                       int positionOffsetPixels)
            {
// 滚动
                scroll(position, positionOffset);


// 回调
                if (onPageChangeListener != null)
                {
                    onPageChangeListener.onPageScrolled(position,
                            positionOffset, positionOffsetPixels);
                }


            }


            @Override
            public void onPageScrollStateChanged(int state)
            {
// 回调
                if (onPageChangeListener != null)
                {
                    onPageChangeListener.onPageScrollStateChanged(state);
                }


            }
        });
// 设置当前页
        mViewPager.setCurrentItem(pos);
// 高亮
        highLightTextView(pos);
    }


    /**
     * 高亮文本
     *
     * @param position
     */
    protected void highLightTextView(int position)
    {
        View view = getChildAt(position);
        if (view instanceof TextView)
        {
            ((TextView) view).setTextColor(getResources().getColor(R.color.dan_hong_5));
        }


    }


    /**
     * 重置文本颜色
     */
    private void resetTextViewColor()
    {
        for (int i = 0; i < getChildCount(); i++)
        {
            View view = getChildAt(i);
            if (view instanceof TextView)
            {
                ((TextView) view).setTextColor(getResources().getColor(R.color.black_5));
            }
        }
    }


    /**
     * 设置点击事件
     */
    public void setItemClickEvent()
    {
        int cCount = getChildCount();
        for (int i = 0; i < cCount; i++)
        {
            final int j = i;
            View view = getChildAt(i);
            view.setOnClickListener(new OnClickListener()
            {
                @Override
                public void onClick(View v)
                {
                    mViewPager.setCurrentItem(j);
                }
            });
        }
    }


    /**
     * 根据标题生成我们的TextView
     *
     * @param text
     * @return
     */
    private TextView generateTextView(String text)
    {
        TextView tv = new TextView(getContext());
        LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
                LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
        lp.width = getScreenWidth() / mTabVisibleCount;
        tv.setGravity(Gravity.CENTER);
        tv.setTextColor(getResources().getColor(R.color.black_5));
        tv.setText(text);
        tv.setTextSize(TypedValue.COMPLEX_UNIT_SP, 16);
        tv.setLayoutParams(lp);
        return tv;
    }


    /**
     * 初始化三角形指示器
     */
    private void initTriangle()
    {
        mPath = new Path();



        mTriangleHeight = (int) (mTriangleWidth / 2 / Math.sqrt(2));
        mPath.moveTo(0, 0);

        mPath.lineTo(mTriangleWidth, 0);
        mPath.lineTo(mTriangleWidth / 2, -mTriangleHeight);
        mPath.close();
    }


    /**
     * 指示器跟随手指滚动，以及容器滚动
     *
     * @param position
     * @param offset
     */
    public void scroll(int position, float offset)
    {
/**
 * <pre>
 *  0-1:position=0 ;1-0:postion=0;
 * </pre>
 */
// 不断改变偏移量，invalidate
        mTranslationX = getWidth() / mTabVisibleCount * (position + offset);


        int tabWidth = getScreenWidth() / mTabVisibleCount;


// 容器滚动，当移动到倒数最后一个的时候，开始滚动
        if (offset > 0 && position >= (mTabVisibleCount - 2)
                && getChildCount() > mTabVisibleCount)
        {
            if (mTabVisibleCount != 1)
            {
                this.scrollTo((position - (mTabVisibleCount - 2)) * tabWidth
                        + (int) (tabWidth * offset), 0);
            } else
// 为count为1时 的特殊处理
            {
                this.scrollTo(
                        position * tabWidth + (int) (tabWidth * offset), 0);
            }
        }


        invalidate();
    }


    /**
     * 设置布局中view的一些必要属性；如果设置了setTabTitles，布局中view则无效
     */
    @Override
    protected void onFinishInflate()
    {
        Log.e("TAG", "onFinishInflate");
        super.onFinishInflate();


        int cCount = getChildCount();


        if (cCount == 0)
            return;


        for (int i = 0; i < cCount; i++)
        {
            View view = getChildAt(i);
            LinearLayout.LayoutParams lp = (LayoutParams) view
                    .getLayoutParams();
            lp.weight = 0;
            lp.width = getScreenWidth() / mTabVisibleCount;
            view.setLayoutParams(lp);
        }
// 设置点击事件
        setItemClickEvent();


    }


    /**
     * 获得屏幕的宽度
     *
     * @return
     */
    public int getScreenWidth()
    {
        WindowManager wm = (WindowManager) getContext().getSystemService(
                Context.WINDOW_SERVICE);
        DisplayMetrics outMetrics = new DisplayMetrics();
        wm.getDefaultDisplay().getMetrics(outMetrics);
        return outMetrics.widthPixels;
    }


}
